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The Sonic Frontiers Phono 1 Special Edition has some remarkable qualities that are shared by some of the best available phono preamplifiers. But before we look further into its sonic qualities, a little history.
All SF products continue to be supported by Parts Connexion which is owned and operated by Chris Johnson, the former chief dude at Sonic Frontiers. His team can repair all and upgrade most SF gear. He has developed an SE+ upgrade for the Phono 1 or Phono 1SE that he says is an improvement over the stock SE. If you are inclined to upgrade components, you might find a stock Phono 1 and then send it to Parts Connexion for the SE+ upgrade. The upgrade will cost about $760, which includes a set of new tubes. There were several SF phono stages. The SFP-1 and SFP-1 Signature were superseded in about 1997 by the Phono 1. The Phono 1SE was introduced in 1999.2 The Phono 1SE offered further parts upgrades from the standard Phono 1, and was the last phono stage produced by Sonic Frontiers. It is said that with the development of the Line 3 line stage preamplifier, the sonic shortcomings of the standard Phono 1 were recognized to be the limiting factor in the Line 3’s ability to make superior music. Hence, the Phono 1SE. According to Chris Johnson, the Phono 1SE is “one of our most elegantly (and thoroughly) designed SFI pieces.” It was the “best measuring tube unit STEREOPHILE ever came across”. The 1SE uses a pair of FET input amplifiers for the first gain stage, followed by four 6DJ8/6922 tubes. Input impedance is adjustable via DIP switches accessible from the rear panel. Anyone who experiments with impedance settings or places their phono stage in a shelf unit which requires you to pull the wires, remove the preamp, open the cover, change the input impedance setting, and then do all of that in reverse, will appreciate the attention to user convenience of having easily accessible switches. Some manufacturers make these required setting changes very inconvenient. I don't understand why. The 1SE comes with a nice tool kit including a pair of cotton gloves for tube handling, a screwdriver, and a set of selected and matched Siemens tubes. The gain is 62 dB (1200x), which is probably sufficient for any low output MC cartridge or associated system. A gain of 54 dB was also available on special order, and if you acquire one of these, the gain can be changed to 62 dB by a competent technician. There is an internal switch to quickly and easily change the front panel Mute switch to provide either low-volume or full mute. Very nice. I used a PS Audio xStream Plus power cord for most of the review, although I tried a couple of others. In my neighborhood, power products normally have a noticeable, but small, effect on the sound. This also depends on the time of day: as the clock approaches midnight, the power gets better and the whole system sounds cleaner and more vivid. Or maybe it's just me. Preamps included a Rowland Synergy IIi, BAT VK-30, Audio Research LS-25 mk. 2, and Cary 300SEI, SLI-80, and BAT VK-300xSE integrated amplifiers. Comparison phono preamplifiers included a Rowland Cadence, Cary PH-302, Aesthetix Rhea, Tom Evans Groove, BAT VK-P20 (internal phono board) and VK-P5, and Conrad Johnson Premier 15 Series II. Tube rolling was fun, and with just four tubes, it is relatively inexpensive. I tried the Siemens, JJs, Mullards, and Amperex Bugle Boys. I did not try the expensive CCa’s, but I encourage those with deep pockets to check them out. The stock Siemens tubes were a bit hard and analytical in my system, although they were very dynamic and had terrific extension in the bass and treble. But with the Bugle Boys… …I found love. Here was the ideal combination of dynamics, resonant and powerful bass, midrange sweetness, highly detailed but never harsh upper midrange, and clean, airy treble. The bass was great; hold on there, it was the midrange that had the special magic that pulls you into a recording; wait a second, it was the clean treble that said this is a superior product. Actually, the entire presentation was uniformly excellent. The bass had exceptional power, going very deep with excellent resonant definition and control. The midrange was very smooth and even, presenting both male and female vocals with realistic precision and presence. And that treble: very extended, fast and detailed with no hint of harshness or grain. Depending on the recording or interconnects, one might suspect that the FET input amplifiers are contributing just a hint of typical solid-state leanness in the midrange and lower treble. This is a small effect, but please note – it is not consistent with all recordings or associated components. Sidebar. This is the rating scale I use for the magnitude of sonic characteristics (thanks to Dr. C.Z. of Denver): “Small” – takes several hours or
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